Production of hydrogen chloride



April 13, 1943. c. H. SMITH 2,316,633

PRODUCTION OF HYDROGEN CHLORIDE Filed April 5, 1941 Spam 50/12/72 ac/d V Patented Apr. 13, i943 oot Gorporation, notation of Delaware PRODUCTION OF HYDROGEN CHLORIDE Claude H. Smith, Talmadge, Ohio, assignor to 1 Wilmington, Dei., a cor- Application April 5, 1941, Serial No. 387,049 2 Claims. (01. 202-57),'

This invention relates to the production of hydrogen chloride and more particularly to the production or dry hydrogen chloride gas by reacting hydrochloric acid with concentrated sulchloride in the form of a dry gas hydrochloric or nuriatic, acid with concentrated acid and releases the hydrogen chloride. in dry, gaseous form. In practice, considerable care. has to be exercised in carrying out this reaction to insure uniform and complete reaction and to prevent the spray and foam ordinarily produced from being carried out of the reactor along with the hydrogen chloride as. Furthermoralf the process is carried out continuously, .if' it necessary to draw off the spent sulfuric acid and unless good mixing is obtained, it may be necessary to use large excesses of sulfuric acid in order to insure eflicient absorption of water and complete utilization of the hydrochloric acid. It is obvious that mechanical agitation is difficult in such an acid mixture.

According to the present invention, gen chloride gas may be produced simply and economically with good mixing and eilicient utilization of the reactants. The description of the invention will be facilitated by reference to the attached drawing, which is a semi-diagrammatical elevation of apparatus suitable for use in the practice of the invention.

Referring to the drawing, hydrochloric acid and concentrated sulfuric acid are separately fed through lines I and 2 respectively into the bottom of a reactor 3; The two acids mix in the bottom of the reactor and react with considerable vigor and the production of heat, and with the attendant formation of a voluminous foam which consists of dry hydrogen chloride gas, spent sulfuric acid and a minor proportion of unreacted hydrochloric acid and concentrated sulfuric acid. The volume of the foam produced is roughly ten times that of the hydrochloric acid employed. The foam rises through the reactor 3, which is filled with suitable packing such as tile, pumice or the like and, in its passage through this packing, is thoroughly agitated and mixed so that the reaction proceeds substantially to completion. Although the foam is relatively unstable, it passes through this packed column without substantial dry hydro- "sulfi'iric acid; The sulfuric acid abstracts the waterfrom the 'muriatic breaking. If any slight breaking of the foam does occur, the condensed liquid are swept on by the fresh oncoming gas and foam, possibly with some attendant airlift efiect. The foam then passes out of the top of the reactor 3 and is led through a pipe 4 into a foam separator 5 which, in order to function efliciently, should have a larger volume than the freespace of the arator 5 the foam, reacted, will expand and break rapidly, releasing the dry hydrogen chloride to pass from the top of the separator through pipe 6 and the spent sulfuric acid to collect in the bottom of the separator and be withdrawn through the pipe 7. Since in practice the apparatus will ordinarily up in the system by any means.

From the foregoing description, it will be ob- During continuous operation, no drain is necessary in the bottom of the reactor to remove spent acid, although such a be provided for cleaning or draining the reactor when it is shut The various parts of the equipment should be constructed from materials which are resistant to the acids with which they are in contact. The reactor is conveniently constructed from commercially available stoneware pipe. Nor does this pipe have to be of abnormally large dimensions. The efliciency of the process is such that a reactor with a 6 inch inside diameter and 5 ft. long Considerable heat is generated in the reaction but release of the hydrogen chloride is facilitated if a small amount of external heat is supplied to the system. This may be done conveniently by heating one or both of the starting acids before introducing them into the reactor.

I claim:

1. A process for continuously producing dry hydrogen chloride which comprises introducing hydrochloric acid and concentrated sulfuric acid into a vessel, reacting them with abstraction of the water from the hydrochloric acid by the sulfuric acidand with the formation of a foam consisting of the reaction mixture. product and spent sulfuric acid, concurrently passing the mixture composing the foam through a packed chamber into a separator. separating the dry hydrogen Patent No. 2,516,655

- drochloric acid and concentrated sulfuric acid into a vessel, reacting them with abstraction of the water frpm the hydrochloric acid by the sulfuric acid and with the formation of a foam consisting of the reaction mixture, product and spent sulfuric acid, concurrently passing the mixture I composing the foam upwardly through a packed chamber into a separator, separating the dry hydrogen chloride from the diluted sulfuric acid and individually drawing of! the dry hydrogen chloride and diluted sulfuric acid.

CLAUDE 8. SMITH.

April 13, 19h

CLAUDE Ii. SMITH- It is hereby certified that error appears in the printed specification "of the above numbered patent requiring correction as follows: Page i, first column, line 21,

for "if it read--it is. at the top ofj the drawing in a position adjacent to the outlet pipe 6 and the legend "dry hydrogen chloride" insert a vertical arrow pointing upward; and

Letters Patent Signed and sealed this 15th day of June, A. D. 19 5.

(Seal) Henry Van Arsdale, 7 Acting Commissioner of Patents.-

that the said' should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

CERTIFICATE OF c ommcmou. Patent no. 2,516,655. April 15, 1 9I+5.

CLAUDE H. SETH.

It is hereby certified that error appears in the printed apecification of the above numbered patent requiring correction as follows: Page 1*, first column, line 21, for "if it read. --it ie at the top oij the drawing in a position adjacent to the 'outlet pipe 6 and the legend "dry hydrogen chloride insert a vertical arrow pointing upward; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 15th o 01 Jane, A. n. 195.

Henry Vm Aredele, (Seal) 1 Acting commissioner of Patente.- 

